Key to beating swine flu

Blood oxygenation appears to be the key to surviving swine flu for patients with respiratory failure, research shows.

A study done by New Zealand and Australian flu investigators between June 1 and August 31, showed most patients who had respiratory failure after contracting swine flu survived if they were treated with extracorporeal membrane oxygenation (ECMO), a type of life support that adds oxygen to the blood.

The study focused on 68 patients with severe swine flu-associated acute respiratory distress, who received ECMO in 15 intensive care units in New Zealand and Australia.

"We looked at a number of factors associated with patients receiving ECMO, such as the incidence, degree of lung dysfunction, clinical features, technical characteristics, duration, complications and survival," Auckland City Hospital cardiothoracic intensive care specialist Shay McGuinness said.

"By doing this we have established the importance of ECMO as a treatment option for patients with severe influenza A H1N1 [swine flu] associated acute respiratory distress.

"Despite the severity of their illness and the lengthy period of time on ECMO life-support, most of these patients survived."

Dr McGuinness said 54 of the 68 patients had survived and 14 had died. Six were still being treated in intensive care units.

"These findings are important to our colleagues all over the world and should be used to facilitate healthcare planning and clinical management for these complex patients during the ongoing pandemic."

The study was to have been published in the Journal of the American Medical Association on November 4, but will be published early online because of the importance of its findings for public health.

Experts in the US and Canada are looking to the innovative methods used in New Zealand and Australia.

Several teams reported yesterday that once swine flu patients are sick enough to need hospital care, they decline very quickly, requiring ventilators and advanced treatments that quickly strain scarce hospital resources.

Writing in the Journal of the American Medical Association, they paint a picture of how cases in younger, previously healthy people in Mexico were relatively mild, but they consumed a vast amount of life-saving therapies.

If the second wave of H1N1 now spreading across much of the world is more severe or broad-based, it may mean some patients will not get the critical life support they need, researchers say.

"This is one of the most difficult conditions I've ever had to treat," said Dr Anand Kumar of St Boniface Hospital in Winnipeg, Canada, a hotspot of infection during the first wave of the swine flu in May and June.

"In the case of Winnipeg, we saw 40 people on ventilators struggling for their lives simultaneously. It's a bizarre and somewhat frightening experience," Dr Kumar said.

While 95 per cent of the patients he studied had some underlying risk factor, most of these were common, such as asthma, smoking, obesity or high blood pressure.

Researchers studying the outbreak in Mexico between March and June 2009 had similar experiences.

They saw critical illness mostly among younger people, who developed severe respiratory failure. About 40 per cent of them died.

Dr Kumar said doctors in Winnipeg used the ECMO system tried in New Zealand for some of their patients who were struggling, despite being on ventilators.

- NZPA, AGENCIES